K_(0)固结珊瑚砂的应力-应变模型及变形参数研究  

Stress-strain model and deformation parameters of K_(0)-consolidated coral sand

作　　者：张季如[1] 彭伟珂 郑颜军 ZHANG Jiru;PENG Weike;ZHENG Yanjun(School of Civil Engineering and Architecture,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]武汉理工大学土木工程与建筑学院,湖北武汉430070

出　　处：《岩土工程学报》2023年第3期478-485,共8页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(42172295)。

摘　　要：珊瑚砂作为岛礁吹填地基的填料,在填筑期的应力路径具有K_(0)固结的特点。利用三轴试验系统对不同初始相对密度的珊瑚砂进行了一系列的K_(0)固结试验,研究了珊瑚砂的应力–应变特性,测试了珊瑚砂的K_(0)系数和颗粒破碎率。基于广义虎克定律,建立了幂函数形式的非线性弹性模型来描述K_(0)固结珊瑚砂的应力–应变关系,提出了变形参数的函数表达式,并将模型计算结果与试验曲线进行了对比。结果表明:K_(0)固结珊瑚砂的应力-应变关系可用幂函数表示。随着轴向有效应力的增加,K_(0)减小,颗粒破碎率增大。在相同的轴向有效应力条件下,珊瑚砂的初始相对密度越小,K_(0)越大,颗粒破碎率越高。在K_(0)状态下,随着轴向有效应力的增加,珊瑚砂的切线模量增加,切线泊松比减小。珊瑚砂的初始相对密度越大,相同轴向有效应力下的切线模量越大,切线泊松比越小。幂函数模型合理地预测了一定应力范围内K_(0)固结珊瑚砂的应力–应变关系,模型及变形参数反映了K_(0)固结的应力路径对应力–应变关系的影响。The stress path followed by soil consolidation in the hydraulic filling site where the coral sand is used as the filling materials is characterized by K_(0)-consolidation. In order to investigate the stress-strain behaviors of the K_(0)-consolidated coral sand, a series of K_(0)-consolidation tests in a triaxial cell are carried out for the coral sands with different initial relative densities.The K_(0)-values of the coral sands are measured and their particle breakage indexes are evaluated. Based on the generalized Hooke’s law, a nonlinear elastic model in the form of a power function is proposed to describe the stress-strain relationship of the K_(0)-consolidated coral sand. The functional expressions for the deformation parameters are presented, and the calculated results of the model are compared with the test curves. The results show that the stress-strain relationship of the K_(0)-consolidated coral sand may be expressed by a power function. With the increase of the axial effective stress, the K_(0)-value decreases, and the particle breakage index increases. Under the same axial effective stress, a small initial relative density corresponds to a large K_(0)-value and a large particle breakage index. As the increase of the axial effective stress in the K_(0)-state, the tangent modulus of the coral sand increases, and the tangent Poisson’s ratio decreases. Under the same axial effective stress, the larger the initial relative density, the larger the tangent modulus, and the smaller the tangent Poisson’s ratio. The stress-strain relationship of the K_(0)-consolidated coral sand with different initial relative densities within a certain stress range is reasonably predicted by the power function model. The model and deformation parameters reflect the influence of the stress path of K_(0)-consolidation on the stress-strain relationship.

关 键 词：应力-应变模型 变形参数 珊瑚砂 K_(0)固结 静止土压力系数 

分 类 号：TU431[建筑科学—岩土工程]